Viscoelasticity and roughness are among the possible causes of the adhesive hysteresis displayed by soft contacts. Viscoelasticity causes an increased effective work of adhesion due to stiffening of the contact, while roughness is responsible for elastic instabilities. Herein, we explore the interplay between viscoelasticity and roughness by simulating in two dimensions the retraction of a rigid cylinder, with wavy surface profile, from a viscoelastic half-space. The wave amplitude and length are varied to induce instabilities in the load–to–area response, while the retraction velocity is increased to promote viscoelasticity. Results show that, in the regime where viscoelasticity is confined to the edges of the wavy contact, the contributions of viscoelasticity and waviness to adhesive hysteresis are nearly independent and additive. At low retraction rates, the instabilities in the load-area curve typical of rough elastic contacts are suppressed by viscoelasticity: the contact stiffens to promote a stable decrease of the contact area with load. This occurs with a minimal change in work of adhesion. However, when the instantaneous limit is met at high retraction rates, mechanical instabilities appear.

粘弹性和粗糙度是软接触显示的粘合剂滞后的可能原因之一。由于接触的硬化，粘弹性导致有效的粘附功增加，而粗糙度是弹性不稳定性的原因。在这里，我们通过在二维中模拟具有波浪形表面轮廓的刚性圆柱体从粘弹性半空间的缩回来探索粘弹性和粗糙度之间的相互作用。改变波幅和长度以引起载荷-面积响应的不稳定性，同时增加回缩速度以促进粘弹性。结果表明，在粘弹性局限于波状接触边缘的状态下，粘弹性和波状对粘合滞后的贡献几乎是独立的和相加的。在低回缩率下，粗糙弹性接触典型的载荷面积曲线的不稳定性被粘弹性抑制：接触变硬以促进接触面积与载荷的稳定减小。这发生在粘附功的最小变化时。然而，当在高回缩率下达到瞬时极限时，就会出现机械不稳定性。